How to Replace an
audi new key G28 Engine Speed Sensor
Charles the Humble Technician teaches you how to replace the G28 Engine Speed Sensor. This sensor is situated near the transmission's edge, above the flywheel gear. It sends a signal to the ECU via an uncolored wire (T55/49), then to the tachometer within the instrument cluster.
1. Engine Speed Sensor
The grey wire is situated at the edges of the transmission, directly above the flywheel ring. The sensor sends an electrical signal through the grey wire to pin T55/49. The ECU utilizes this information to regulate boost and fuel. It also sends an indicator to the G5 Tachometer located in the instrument cluster.
The sensor is used as a reference point to connect with the G40 Camshaft Position Sensor. The ecu must know when the crankshaft has reached TDC and also where the camshaft lies to trigger the spark and injectors.
If this sensor fails, the ECU will show an error code P00160 which indicates that the Crank Shaft and Intake Camshaft are not in sync and could indicate the chain stretching or a jump link on the upper timing chain. The code won't show without the additional information supplied by other sensors (G4 or G40).
It's a bit tricky to test because there are several connector pins, and they all have different functions. The best method for doing this is by measuring the resistance between the ECU and the sensor. When the sensor is functional,
replacement audi key cost uk it should read about 1000 ohms. If you are having problems with this component, look for signs of oil or coolant in the connector bay.
2. Injectors
Yesterday, when i was accelerating to the fullest speed from highway paytoll i had a big cut in power like the engine is running out of gas or the injectors aren't firing any more. In the morning, i removed the spark plugs, three were soaked with gazoline and the fourth was dry. When i crank the engine without sparks, I put a piece of tissue on top of each injector hole and the 3 that were drenched in gazoline pop out, but the 4th stays closed. I tested the ground connection of ECU pins 14,30, and 48/55. I got 0ohm. So i assume the problem is somewhere else.
I also tried to reset the PID without success. The car is able to start if the G28 is not plugged in and is running fine when it is plugged in but it still is experiencing intermittent misfires at higher RPM. The coolant sensor (G62) even if it is not plugged in, shows a temperature of -49c. Also, i noticed that the gauge for oil pressure in the cockpit shows 2 bar while the actual pressure is 0.0 when i rev the engine.
I'm not sure what to do. I believe that I've all other possibilities out. I'm worried that i might have missed something. If anyone has any suggestions, please chime in! TIA!
3. Fuel Pump
The fuel pump of the g28 gets a signal from the RPM sensor. The GM-style sensor is identical to the G4 and both function in the 80 100, 200, UrS and RS2 cars which is why you can easily locate one at a wrecking yard or at a parts store. It is simple to test them by putting your DMM in resistance mode and measure between pins 1 (with the bump on the connector's end up) and 2 (2nd from the left on the black end of the connector). They must be infinite Ohms.
4. ECU
The ECU of our 20vt turbo (3B AAN ABY) engines needs to know both the speed and position of the crankshaft to determine timing of fuel injectors, etc. It utilizes a Crank Position Sensor G4 and an Engine Speed Sensor G28 to achieve this. If you are experiencing issues with either one of these, the diagnostic scanner will show the codes that could trigger an engine shut down.
The signs of a malfunctioning G28 sensor include an inaccurate rev counter for the gearbox and gears that shift faster than normal and/or misfiring when you're in gear. It is likely that your sensor is failing and needs to be replaced if you encounter any of these symptoms. The good thing is that they are very affordable and easily accessible particularly in the case of a Bosch unit like ours. Alternately, GM's version this part is an option.
5. Tachometer
A faulty engine speed sensor could be a cause for a slew of issues with your car. It's an essential component of the transmission of your
audi key programming since it sends information to the ECU regarding how fast or slow the engine is spinning. This sensor can cause the transmission to fail and other
audi car key holder components to be affected.
The G5 engine speed sensor is situated on the outside of the transmission above the flywheel ring gear and sends a signal directly to the ECU at pin T55/49, via a grey wire. The ECU utilizes this signal to control fuel and boost, and also to timigrate. It also transmits it to the G5 Tachometer located in the instrument cluster. You can check for sensor failure by checking continuity from the sensor to the tachometer. You can also verify continuity between pin T55/49 of the ECU and pin T6a/1 of the instrument cluster (trace [79]) and between pin T6a/1 and
lost pin T26a/12. You should see a resistance of approximately 1000 ohms between these two points. This is a standard part across the
audi key shell 80 100 200, UrS and RS2 range from 1985 MC to the 1997 UrS AAN and 1995 RS2 ADU. Good parts could be found in wrecking yards.